With a few million more mobile device users than there were just a few months ago, the lack of security is scaring internet safety experts.
"Fewer than 5% of people have got some form of security on their mobile devices but it's super critical," says Norton online safety advocate Marian Merritt.
Still, surpassing the probability of someone hacking your smartphone or tablet is the risk of you losing it.
Merritt suggests you start the new year by changing to a strong password.
Then, install security software.
Meanwhile, Dave Marcus at McAfee warns there are a lot of fake apps out there, all intended to steal from you.
One in particular looks like a harmless game, but actually embeds a hidden texting charge in your monthly cellphone bill.
A problem with infected QR codes, which are supposed to be scanned by mobile devices, has also popped up.
"It may not be the fact that the QR code itself is infected, so to speak, but it takes you to a malicious sight or it downloads a malicious app," Marcus explains.
He recommends only clicking on QR codes that belong to a known advertiser or vendor.
Those codes are least likely to be infected.